r dr r

boy = me. girl = girl.

girl: bai
boy: r^2 dr
boy: hahahaha

girl: haha
boy: (3 r^2 dr) / 3
boy: ok. i'm really going now.
boy: dy = (3 r^2 dr) / 3

girl: omg
girl: :)
girl: you are forgetting who you're typing to

and you wonder where my charm comes from. um... perhaps i should go to bed.